Electrolytic cell and the process of electrolyzing metal.



C. DANTSIZEN. ELECTROLYTIC CELL-AND THE PROCESS OF ELECTROLYZING METAL.

APPLICATION FILED MAR. 20| i9l5- Patented July 4, 1916.

lnve ntor: Christian Dantsizen W W His fltto'rn eg.

UNITED STATES PATENT OFFICE.

CHRISTIAN DANTSIZEN, OF SCOTIA, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTROLYTIC CELL AND THE PROCESS OF ELECTROLYZING METAL.

To all whom it may concern Be it known that I, CHRISTIAN DANTsI- ZEN, a citizen of the United States, residing I "at Scotia, in the county of Schenectady,

AMetal, of which the following is a specification.

The present invention relates to the electrolysis of an earth metal, particularly magnesium, and its object is to enable the elec trolyzed metal to be obtained in relatively large masses.

When magnesium, or beryllium, .is electrolyzed from a fused electrolyte in a cell having an ordinary carbon or iron cathode, the metal separates out in small globules which are recovered with difficulty from the bath. I have discovered that when a metal cathode is used alloying very slowly .with the magnesium or other metal to be electrolyzed, the electrolyzed molten metal adheres to the electrode and collects in large masses.

In the accompanying drawings Figure -1 1- a alt electrolytic cell illustrating my invention; Figs. 3 and 4 illustrate diagrammatically diflerent arrangements of the elec trodes. I

The cell comprises a container 1, consisting of suitable inert material, such as magnesite brick. The electrolyte 2 may consist for example of a mixture of potassium chlorid and magnesium chlorid, the relative weights of the two materials at the begin ning of the electrolyzing operation'being preferably in the ratio of then molecular weights. In some cases two orv three per cent. of calcium fluorid may be added to the electrolyte with advantage. Molten mag- -nesiu.m has a specific gravity somewhat less than the electrolyte and hence the metal separated clings to the electrode and tends to rise to the surface of the electrolyte. The

cell may have a plurality of anodes 3 which may consist of conductive material inert with respect to the electrolyte, for example, carbon. The cathode 4 consists of material remaining solid or unfused during the operation of the cell and the surface of the cathode consists of a material which slowly alloys with the metal to be electrolyzed.

Specification of Letters Patent.

plan viewand Fig. 2 a sectional view of For example, in the case of magnesium I- prefer to use galvanized or sherardized Iron as cathode. The exterior of the surface of such an electrode consists'l argely of zinc, and below this zinc layer is a layer of zinc-iron alloy of Variable proportions, the proportion of zinc gradually decreasmg toward the inner iron base. su table direct current'is supplied by the conductors 5, 6 to the electrolyte in a molten state, the magnesium separates out at When a- Patented July 4., 1916.

Application filed March 20, 1915. Serial No. 15,740.

the cathode, rapidly alloys with the ex terio-r zinc layer and then more slowly alloys W1th the zinc in the layer of zinc-iron alloy until an equilibrium is reached. The

molten metal wets the surface of the zinciron alloy and hence remains attached. In

place of zinc, the surface of the iron electrode may be alloyed with tin or copper-.

The surface alloyage with cop er may be produced by dipping the iron el ctrode into molten copper in a hydrogen atmosphere. Instead of a galvanized iron cathode, an alloy of iron and nickel containing a small percentage of nickel may be used as cathode.

An advantage is obtained bythe use of a plurality of cathode conductors wetted by the electrolyzed metal, as globules of' molten metal on one rod unite with globules on another rod to form large masses.

When a plurality of rods are used'the mass of accumulated molten metal which will adhereto the cathode is not only larger but remains stationary on one side of the cathode as in dicated. As the electrolysis continues, the

lump of magnesium 7 increases without separating from the cathode until the bath has been depleted of magnesium salt and no lumps of magnesium exist in the bath which are not electrically part of the cathode. Recombination. of magnesium with chlorin is thus avoided.

The cathode 4. illustrated in Figs. 1 and or by placing the rods to partially inclose the accumulated lump of magnesium, as shown in Fig. 4. The amount of zinc which alloys with the metallic magnesium is so extremely small it may be neglected for any of the known commercial uses of metallic magnesium.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. An electrolytic cell for isolating metallic magnesium comprising a container, an anode inert with respect to a molten electrolyte containing magnesium compounds and a cathode remaining unfused during the electrolysis of the magnesium and having a surface layer wetted by molten magnesium.

tainer, a magnesium-containing electrolyte which is molten during operation of the cell, an anode, and a cathode consisting of material not readily alloyable with magnesium and remaining unfused during the electrolysis of magnesium, the surface of which is alloyed with zinc.

5. An electrolytic cell comprising a con tainer, an electrolyte of fused salts containing an earth metal, an anode, anda cathode of iron in contact with said electrolyte, the surface of said cathode consisting largely of a metal other than iron wetted by a metal electrolyzable from said electrolyte.

6. An electrolytic cell comprising a container, an. electrolyte of fused salts, an anode, and a plurality of unfused cathode conductors in contact with said electrolyte, the surface of said conductors being wetted by the molten metal separating from the electrolyte and located so closely to each other that the metal accumulating on the respective conductors will unite into a large mass clinging to the several conductors.

7. An electrolytic cell comprising a container, an electrolyte of fused magnesium salts, an anode, and a cathode of iron, having a surface layer of zinc-iron alloy.

8.An electrolytic cell comprising a con tainer, an electrolyte of salts of magnesium}, an anode, and a cathode of iron, a surface) layer of which is alloyed with zinc, their: outer surface consisting largely of zinc, and the proportion of zinc gradually decreas ing toward'the interior. a

9. The process of collecting by electrolysis metal tending to separate from a fused e5 electrolyte in small globules which consists in separating said metal out at a cathode, the surface only of which is sufiiciently alloyable with 'the metal electrolyzed to be wetted thereby, thus causing the accumulation of the metal in masses on the cathode.

10. An electrolytic cell comprising a container, a molten electrolyte therein, containing a compound of a metal tending to electrolyze out in small globules, an inert anode, and a cathode remaining unfusecl. during the electrolysis, and consisting of a material alloying substantially at the sur;- face only with the metal separated by electrolysis, thereby causing said metal to clinl' to the cathode in large masses. i

In witness whereof, I have hereunto set my hand this 18th day of March 1915.

CHRISTIAN DANTSIZEN. 

